This invention relates to a composition and a method for forming a tile body.
Conventional ceramic tiles are manufactured from ceramic materials, generally by the production of a tile body or biscuit which is fired in excess of 700.degree. C., followed by the application of a decorative glaze to the tile body or biscuit, which is then fired in excess of 1000.degree. C. The preparation of the tile body or biscuit and the subsequent glazing can be either separate operations, or carried out in a single firing operation. This manufacturing method is characterised by high energy consumption, the difficulty of achieving fine printing as a result of the glaze moving at very high temperatures, quite considerable wastage and breakage during the manufacturing method as a result of the release of stresses and tensions on cooling of the tiles, and high capital equipment requirements. Despite the fact that such tiles are capable of lasting for many years, fashion dictates that tiles such as bathroom and kitchen wall and floor tiles should be changed at regular intervals which interval may be as little as four to eight years. There is thus a need for a method of making a tile which may be used as a wall or a floor tile, which method is economic yet leads to a product with suitable properties of wear resistance and appearance.
U.S. Pat. No. 4,729,853 to Bayer AG discloses a flame retarding sealing composition and articles made therefrom such as panels, which consists of 10 to 50% by weight of a hydraulic binder selected from gypsum (calcium sulphate) and plaster of paris, 20 to 60% by weight of a dehydratable filler selected from the group consisting of aluminium hydroxides, aluminium hydrated oxides and hydrated alumina, 10 to 60% by weight of a melamine which may be melamine formaldehyde, 3 to 30% by weight of a polymer dispersion and optionally a pigment or an inorganic phosphorous-containing compound. The dehydratable filler must be one which "consumes" heat by a decomposition reaction or by evaporation, so that it assists in the flame retardation. The melamine component serves several useful functions in relation to flame retardation including the emission of gases which bond hydrogen halides as ammonium salts, which is a significant factor in the field of electrical installations, and in that it consumes energy during this decomposition process causing a heat discharge mechanism independent of the dehydration of the sealing compound and its fillers. The polymer dispersion is added to impart elasticity to the sealing composition and for dust prevention purposes. The essential components of the sealing composition are the hydraulic binder, the dehydratable filler and the melamine formaldehyde. There is no disclosure in this patent that the sealing composition may be used to form a tile body.